1. Technical Field of the Invention
The present invention relates to a power supply apparatus for vehicles, which transfers electrical power between a battery installed in a vehicle and a power supply outside the vehicle.
2. Related Art
Vehicle power supply systems are well known. As one of such vehicle power supply systems of conventional art, JP-A-2008-220130 discloses a vehicle power supply system that includes two charging means which are a conductive charging means and an inductive charging means. The conductive charging means allows transfer of electrical power between a battery installed in the vehicle and a residential power supply, which are in an electrically and physically connected state. The inductive charging means allows transfer of electrical power between the battery and an inductive charger outside the vehicle, which are in a magnetically connected state.
In the conductive charging means, upon connection between the residential power supply and the vehicle via a connector, commercial AC power from the residential power supply is converted into DC power by an inverter to charge the battery. In the inductive charging means, self-induction electromotive force is caused in a pad of the inductive charger. The self-induction electromotive force causes mutual-induction electromotive force in a vehicle-side port. The voltage induced in the port is rectified into DC voltage by a rectifier circuit to charge the battery. Thus, the vehicle power supply system disclosed in the patent document JP-A-2008-220130 enables two types of charging, i.e. conductive charging and inductive charging.
However, in the vehicle power supply system disclosed in the patent document JP-A-2008-220130, the conductive charging means includes an inverter used for power conversion, while the inductive charging means also includes a rectifier circuit used for power conversion (rectification). In other words, each charging means has a power converter of its own. Therefore, the system as a whole has a problematically large size occupying a large space when installed in a vehicle. The large size of the system also raises a problem of increasing weight and cost.
In addition in the vehicle power supply system disclosed in JP-A-2008-220130, two charging means are individually provided for the conductive charging means and the inductive charging means, for use in charging electrical power to the power storage section. Therefore, the charging means as a whole have a large size, which leads to increase of cost of the system.